body {
  padding: 0;
  margin: 0;
  font-size: 14px;
  background-color: #f5f5f5;
  color: #333;
}

.box {
  width: 200px;
  height: 200px;
  background-color: orange;
  margin: 0 auto;
  margin-top: 100px;
  text-align: center;
  line-height: 200px;
  color: #fff;
}

.container {
  width: 100%;
  height: 100%;
  background-color: #000;
  opacity: 0.5;
  position: fixed;
  top: 0;
  left: 0;
  display: none;
}

